Perturbation of Staphylococcus aureus Gene Expression by the Enoyl-Acyl Carrier Protein Reductase Inhibitor AFN-1252

Parsons, Joshua B.; Kukula, Maciej; Jackson, Pamela; Pulse, Mark; Simecka, Jerry W.; Valtierra, David; Weiss, Jason; Kaplan, Nachum; Rock, Charles O.

doi:10.1128/aac.02307-12

Cited by 31 publications

(36 citation statements)

References 63 publications

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“…ESAT-6 operon transcription is inhibited by SaeRS signaling (16), and its up-regulation was consistent with a connection between the genes altered by SaeRS and FakA. Quantitative RT-PCR verified that these three SaeRS-regulated genes (12,13) were expressed at significantly lower levels in ΔfakA and ΔfakB1 ΔfakB2 strains, and the single FakB deletions had intermediate phenotypes (Fig. 4D).…”

Section: [ 14 C]fas To the Two Fakbsmentioning

confidence: 71%

“…4E). Our previous work shows that the elimination of acyl-PO 4 production by FASII using AFN-1252 to block FabI, there is a strong down-regulation of these same SaeRS-controlled virulence genes in S. aureus (13). This result suggests that FASII, in addition to FakA, provides acyl-PO 4 to support virulence factor transcription.…”

Section: Discussionmentioning

confidence: 89%

“…The initial observation that ΔfakA mutants were defective in α-hemolysin production (5) is not because of FakA alone, but rather Fak activity is the responsible entity. Our analysis indicates that multiple virulence factors whose transcription is regulated by Fak activity are related to the genes regulated by the SaeRS two-component system (12,13,16), suggesting that Fak may function in the SaeRS biochemistry. It is tempting to speculate that FakB(acyl-PO 4 ) acts as a phosphorelay component much like acetyl-phosphate in Gram-negative bacteria, where its role in the phosphorylation of response regulator receiver domains is established (35).…”

Section: Discussionmentioning

confidence: 99%

“…Of note was that transcription of numerous virulence related genes (including α-hemoslysin, hla) were uniformly attenuated in the ΔfakA knockout (Table S2). Many of these virulence factors (saeP, ehp, efb, and so forth) are also known to be regulated by the SaeRS system (12,13). The transcription of the early secreted antigenic target 6 kDa protein (ESAT-6) protein secretion system for the export of EsxA and EsxB was activated in the ΔfakA strain (Table S2).…”

Section: [ 14 C]fas To the Two Fakbsmentioning

confidence: 93%

“…Next, 40 μL of the reaction was spotted on DE81 disks and washed three times with ethanol containing 1% acetic acid to remove the unreacted FA. Quantitative real-time PCR was performed as previously described (13). Full details are provided in SI Materials and Methods.…”

Section: Ah1263mentioning

confidence: 99%

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Identification of a two-component fatty acid kinase responsible for host fatty acid incorporation by Staphylococcus aureus

Parsons

Broussard

Bose

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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Extracellular fatty acid incorporation into the phospholipids of Staphylococcus aureus occurs via fatty acid phosphorylation. We show that fatty acid kinase (Fak) is composed of two dissociable protein subunits encoded by separate genes. FakA provides the ATP binding domain and interacts with two distinct FakB proteins to produce acyl-phosphate. The FakBs are fatty acid binding proteins that exchange bound fatty acid/acyl-phosphate with fatty acid/acyl-phosphate presented in detergent micelles or liposomes. The ΔfakA and ΔfakB1 ΔfakB2 strains were unable to incorporate extracellular fatty acids into phospholipid. FakB1 selectively bound saturated fatty acids whereas FakB2 preferred unsaturated fatty acids. Affymetrix array showed a global perturbation in the expression of virulence genes in the ΔfakA strain. The severe deficiency in α-hemolysin protein secretion in ΔfakA and ΔfakB1 ΔfakB2 mutants coupled with quantitative mRNA measurements showed that fatty acid kinase activity was required to support virulence factor transcription. These data reveal the function of two conserved gene families, their essential role in the incorporation of host fatty acids by Gram-positive pathogens, and connects fatty acid kinase to the regulation of virulence factor transcription in S. aureus.T he pathway for the uptake and incorporation of host fatty acids (FA) by bacterial pathogens is important to understanding their physiology and determining if type II fatty acid synthesis (FASII) inhibitors will be useful antibacterial therapeutics. FASII is an energy-intensive process, and the advantage of being able to use host FA for membrane assembly obviously allows ATP to be diverted to the synthesis of other macromolecules. Gram-positive pathogens are capable of incorporating extracellular FA into their phospholipids. In species related to Streptococcus agalactiae, extracellular FA can completely replace endogenously synthesized FA, rendering the FASII inhibitors ineffective growth inhibitors if sufficient FA are present (1, 2). In contrast, FASII inhibitors exemplified by the enoyl-acyl carrier protein (ACP) reductase therapeutic AFN-1252 are effective against Staphylococcus aureus, even when extracellular FA are abundant (2, 3). A major impediment to our understanding of this diversity is that the pathway and enzymes responsible for the incorporation of extracellular FA is not established in the Firmicutes. A recent analysis of a ΔplsX knockout strain of S. aureus ruled out a role for either acyl-CoAs or acyl-ACP as intermediates in host FA metabolism and instead provided evidence for the existence of a new enzyme that phosphorylates FA, called FA kinase (Fak) (4) (Fig. 1A). Host FA are phosphorylated by Fak, and the acyl-PO 4 formed is either used by the PlsY glycerol-3-phosphate acyltransferase or converted to acyl-ACP by PlsX. The acyl-ACP may be either elongated by FASII or used by PlsC. Despite the strong evidence for their existence, the genes/proteins that encode this novel enzyme in FA metabolism were previously unidentif...

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Section: [ 14 C]fas To the Two Fakbsmentioning

confidence: 71%

Section: Discussionmentioning

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Section: [ 14 C]fas To the Two Fakbsmentioning

confidence: 93%

Section: Ah1263mentioning

confidence: 99%

See 3 more Smart Citations

Identification of a two-component fatty acid kinase responsible for host fatty acid incorporation by Staphylococcus aureus

Parsons

Broussard

Bose

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

142

230

View full text Add to dashboard Cite

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Bacterial fatty acid metabolism in modern antibiotic discovery

Yao

Rock

2017

Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biolog

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Bacterial fatty acid synthesis is essential for many pathogens and different from the mammalian counterpart. These features make bacterial fatty acid synthesis a desirable target for antibiotic discovery. The structural divergence of the conserved enzymes and the presence of different isozymes catalyzing the same reactions in the pathway make bacterial fatty acid synthesis a narrow spectrum target rather than the traditional broad spectrum target. Furthermore, bacterial fatty acid synthesis inhibitors are single-targeting, rather than multi-targeting like traditional monotherapeutic, broad-spectrum antibiotics. The single-targeting nature of bacterial fatty acid synthesis inhibitors makes overcoming fast-developing, target-based resistance a necessary consideration for antibiotic development. Target-based resistance can be overcome through multi-targeting inhibitors, a cocktail of single-targeting inhibitors, or by making the single targeting inhibitor sufficiently high affinity through a pathogen selective approach such that target-based mutants are still susceptible to therapeutic concentrations of drug. Many of the pathogens requiring new antibiotic treatment options encode for essential bacterial fatty acid synthesis enzymes. This review will evaluate the most promising targets in bacterial fatty acid metabolism for antibiotic therapeutics development and review the potential and challenges in advancing each of these targets to the clinic and circumventing target-based resistance.

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